Question 1

Which item below is most resistant to phagocytosis?

Accepted Answer

Encapsulated bacteria, such as many Gram-negative cocci, are more resistant to phagocytosis because their capsule can inhibit or evade the immune response, making it harder for phagocytes to engulf and destroy them.

Question 2

All of the following are functions of monocytes/macrophages except

Accepted Answer

Monocytes/macrophages do not directly lyse host cells infected with viruses; this function is primarily associated with natural killer cells and cytotoxic T lymphocytes. Monocytes/macrophages are involved in antigen presentation, cytokine secretion, and phagocytosis of debris.

Question 3

Neutrophils have receptors for which portion of the antibody molecule?

Accepted Answer

Neutrophils have receptors for the Fc (constant fragment) portion of the antibody molecule, which allows them to recognize and bind to antibodies that are attached to pathogens, facilitating phagocytosis.

Question 4

Each of the following is one of the four basic characteristics of inflamed tissue except

Accepted Answer

Bruising is not considered one of the four cardinal signs of inflammation. The four basic characteristics of inflamed tissue are pain, heat, swelling, and redness. Bruising is related to the escape of blood from the vascular system into tissues, which is not a primary characteristic of inflammation.

Question 5

The granules in mature neutrophils contain all of the following except

Accepted Answer

Histamine is primarily found in the granules of mast cells and basophils, not in neutrophils. Neutrophils contain various enzymes and proteins like alkaline phosphatase, lysozyme, and gelatinase that help in killing and digesting microorganisms, but they do not store histamine.

Question 6

The process by which neutrophils leave blood vessels, squeezing between the endothelial cells to enter the tissues, is called

Accepted Answer

Diapedesis is the process through which neutrophils and other leukocytes exit the bloodstream by squeezing between endothelial cells of the blood vessel walls to reach the site of infection or injury in the tissues.

Question 7

Each positive acute phase reactant below is paired correctly with its function except

Accepted Answer

Fibrinogen's primary function is to aid in blood clot formation, not specifically the activation of fibroblast cells.

Question 8

What is the exact structure to which an antibody or T cell receptor will bind?

Accepted Answer

Epitopes are the specific parts of an antigen that are recognized and bound by antibodies or T cell receptors. These are precise molecular structures (such as a sequence of amino acids in the case of proteins) on the surface of an antigen that the immune system identifies and responds to.

Question 9

Each chemical below is paired correctly with its antimicrobial effect except

Accepted Answer

Lactoferrin is known for its ability to bind iron, not complex carbohydrates like lactose, thereby inhibiting bacterial growth by depriving them of the iron needed for metabolism.

Question 10

Which cell(s)below is (are)capable of immunologic memory?

Accepted Answer

T lymphocytes are capable of immunologic memory, allowing the immune system to remember and respond more rapidly and effectively to pathogens that have been encountered previously.

Question 11

How is increased tissue fluid in an inflamed site beneficial?

Accepted Answer

Increased tissue fluid in an inflamed site is beneficial because it brings nutrients to white blood cells, dilutes toxins, brings humoral immune system components such as complement and antibodies, and brings coagulation proteins for fibrin formation and localization of the problem.

Question 12

Which cell type(s)below are associated with lysis of tumor cells?

Accepted Answer

Lymphokine activated killer (LAK) lymphocytes are specifically known for their ability to lyse tumor cells. They are a type of immune cell that can be activated to target and destroy cancer cells.

Question 13

Which immunoglobulin subclass below resides exclusively on the surface of B cells and serves a regulatory function?

Accepted Answer

IgD is primarily found on the surface of immature B-lymphocytes and plays a role in the initiation and regulation of immune responses.

Question 14

A clinical laboratory scientist observed a peripheral blood smear and noticed one to two pale blue inclusions in several neutrophils. Which of the following would be consistent with this observation?

Accepted Answer

The presence of pale blue inclusions in neutrophils, along with the other observations mentioned, suggests an inflammatory or infectious process. C-reactive protein is an acute phase reactant that increases in response to inflammation. Neutrophils with vacuoles and a high total white blood cell count with absolute neutrophilia are also indicative of an infection or inflammation. Decreased serum albumin and transferrin can occur in chronic disease states, which may also be associated with the observed changes in neutrophils.

Question 15

Which tissue(s)below is (are)considered primary lymphoid tissue? (Choose as many as apply.)

Accepted Answer

The thymus and bone marrow are considered primary lymphoid tissues because they are where lymphocytes (T cells and B cells, respectively) mature.

Question 16

How does normal microbial flora on the human body prevent infection?

Accepted Answer

Normal microbial flora competes with pathogens for nutrients and space, making it difficult for pathogens to establish and grow.

Question 17

When an antibody is bound to an antigen, which complement path(s)is (are)activated?

Accepted Answer

The classic pathway is activated when antibodies bind to antigens, forming antigen-antibody complexes.

Question 18

All of the following are chemotactic compounds except

Accepted Answer

The answer of All of the following are chemotactic compounds...

Question 19

Natural killer lymphocytes may be distinguished from other lymphocytes because they

Accepted Answer

Natural killer (NK) cells can be distinguished from other lymphocytes by all the listed characteristics: they possess CD56 and CD16 cell surface markers, lack the CD3 marker, are typically larger with azurophilic granules, and do not have immunoglobulin or specific antigen receptors.

Question 20

The digestive enzymes of phagocytic cells are contained in the

Accepted Answer

The digestive enzymes of phagocytic cells are contained in granules, which are specialized organelles that fuse with phagosomes to degrade ingested material.

Quiz 2: Overview of the Immune System